World Immunisation Week will be observed globally from tomorrow until  April 30, and the World Health Organisation has urged countries to reach out to children who are still not protected from vaccine-preventable diseases.

Immunisation, one of the most cost-effective public health interventions, saves two to three million lives every year.

In 2011, nearly 30 million children were immunised against diphtheria, tetanus and pertussis (three doses of DTP/pentavalent vaccine) in the 11 member countries of the World Health Organis-ation’s Southeast Asia region: Bangladesh, Bhutan, the Democratic People’s Republic of Korea, India, Indonesia, the Maldives, Myanmar, Nepal, Sri Lanka, Thailand and Timor-Leste.

These are the most basic vaccines that serve as an indication of how many children are protected from common diseases.

Although progress has been made, estimated coverage in the region remained stagnant at 75 per cent in 2011.

As a result, an estimated nine million children were not immunised with these vaccines in that year.

Between 2000 and 2011, coverage of measles-containing vaccines in the Southeast Asia region increased from 61 to 79 per cent.

But at the current pace, the region will not reach the 2015 goal of reducing measles mortality by more than 95 per cent.

Although efforts to accelerate measles control through supplementary immunisation campaigns have reduced the number of child-ren susceptible to measles, progress needs to be accelerated to move faster than the disease.

In 2012, India, Myanmar and Nepal conducted successful measles vaccination campaigns in which more than 46 million children were immunised, protecting susceptible youngsters against the virus.

Countries in the region must intensify efforts to reach high-risk, mobile and under-served populat-ions to protect children from these vaccine-preventable diseases.

“Equity and access must remain the focus of our immunisation programs,” Dr Samlee Plianbangchang, the WHO’s director for Southeast Asia, says.

“Immunisation is a proven investment with high returns for public health and economic growth.

“Countries in southeast Asia must recognise that immunisation plays a critical role in ensuring that development is not stifled by a growing disease burden.

“They must implement strategies to increase immunisation coverage and surveillance performance.”

Polio eradication reached a milestone in the region by achieving a second year with no wild polio virus reported since the last case was recorded in India in January, 2011.

Although it’s an important milestone, polio-free status requires sustained high performance, sensitive surveillance networks and ensuring any wild polio virus is quickly detected if imported.

Emergency preparedness and response plans have been put in place for countries to deploy rapid-response teams to prevent transmission if any cases are reported.

With the support of the WHO and the US Centers for Disease Control and Prevention, countries in the region are implementing risk assessments at national and sub-national levels using new tools and methods developed for informing strategies to avoid polio outbreaks through importation.

Efforts are also under way to ensure the region remains on track for certification next February.

With support from immunisation partners, including the GAVI Alliance, countries are using funding opportunities to introduce new vaccines to protect their populations.

Lessons learned from anti-polio campaigns can improve national immunisation programs.

When introducing new technol-ogies, countries must use evidence-based data and robust disease-burden studies to decide which vaccines to introduce. To inform the decision-making process, they should also consider the issue of financial sustainability.

Lifting public awareness of immu-nisation will save millions of lives.